Detailed Description
In order to describe the technical contents, the achieved objects and effects of the present invention in detail, the following description will be made with reference to the embodiments in conjunction with the accompanying drawings.
The most critical concept of the present invention is that the ground radiating unit 22 includes a horizontal radiator 221, a first vertical radiator 222, a second vertical radiator 223, and an additional radiator 224, the first vertical radiator 222 and the second vertical radiator 223 being connected to the middle and end portions of the horizontal radiator 221, respectively, and the additional radiator 224 being connected to the middle portion of the first vertical radiator 222.
Referring to fig. 1, 2, 3 and 10 and 11, an ultra wideband 5G MIMO antenna structure includes a PCB board 1 and more than one antenna assembly 2, the more than one antenna assembly 2 is disposed on the PCB board 1 at intervals, the antenna assembly 2 includes a feeding unit 21 and a grounding radiation unit 22 coupled to the feeding unit 21, and the feeding unit 21 corresponds to a feeding point on the PCB board 1; the grounding radiation unit 22 comprises a horizontal radiator 221, a first vertical radiator 222, a second vertical radiator 223 and an additional radiator 224, wherein the top end of the first vertical radiator 222 is connected to the middle part of the horizontal radiator 221, and the bottom end of the first vertical radiator 222 is connected with a grounding point on the PCB board 1; the top end of the second vertical radiator 223 is connected to the end of the horizontal radiator 221, and a space is provided between the bottom end of the second vertical radiator 223 and the PCB 1; the additional radiator 224 is connected to the middle of the first vertical radiator 222.
From the above description, the beneficial effects of the invention are as follows: the protruding additional radiator 224 is arranged on the first vertical radiator 222, so that the current path is prolonged, and the low-frequency broadband of the antenna is effectively widened; the second vertical radiator 223 is arranged at the end part of the horizontal radiator 221, so that the size of the antenna in the horizontal direction can be effectively reduced, and the current distribution of the whole antenna is changed, so that the antenna has good isolation performance during high-frequency operation; the special structures of the feed unit 21 and the grounding radiation unit 22 are arranged, so that the antenna structure can form two adjacent double resonances, all frequency bands at 6GHz in fifth-generation mobile communication can be effectively covered, and the antenna efficiency and the isolation between the antenna units can well meet the requirements; the invention has the characteristics of vertical placement and lower height, and can better meet the design requirements of the current full-screen mobile terminal.
Further, the feeding unit 21 includes a horizontal branch 211 and a vertical branch 212, a top end of the vertical branch 212 is connected to the horizontal branch 211, and a bottom end of the vertical branch 212 includes a feeding point; the horizontal branch 211 is arranged close to the horizontal radiator 221 and the vertical branch 212 is arranged close to the additional radiator 224.
As is apparent from the above description, the feeding unit 21 and the ground radiating unit 22 can be well coupled.
Further, the projection of the horizontal branch 211 in the plane of the ground radiating element 22 is partially overlapped with the horizontal radiator 221; the projection of the vertical branch 212 in the plane of the ground radiating element 22 overlaps with the additional radiator 224.
Further, the feeding unit 21 is T-shaped, and the top end of the vertical branch 212 is connected to the middle of the horizontal branch 211.
Further, the feeding unit 21 is L-shaped, the top end of the vertical branch 212 is connected to the end of the horizontal branch 211, and the horizontal branch 211 and the second vertical radiator 223 are located on the same side of the vertical branch 212 or on opposite sides of the vertical branch 212, respectively.
As is clear from the above description, the present solution is two other arrangements of the feeding unit 21 for generating high frequency resonance.
Further, the feeding unit 21 is disposed at a side of the grounding radiation unit 22, and a plane where the feeding unit 21 is located is parallel to a plane where the grounding radiation unit 22 is located.
Further, the additional radiator 224 is connected to a side of the first vertical radiator 222 remote from the second vertical radiator 223.
As can be seen from the above description, the additional radiator 224 is disposed on the side far from the second vertical radiator 223, so that the effective length of the current can be maximized, and a sufficient low frequency bandwidth of the antenna structure is ensured.
Further, the additional radiator 224 is integrally provided with the first vertical radiator 222.
Further, the number of the antenna assemblies 2 is an even number more than four, and the even number of the antenna assemblies 2 more than four are symmetrically distributed on two opposite sides of the PCB board 1.
As can be seen from the above description, the 5g 6x6 or 8x8MIMO antenna system is more suitable for handheld devices, and the left and right sides of the PCB board 1 are respectively provided with a plurality of antenna assemblies 2, and the intervals between the plurality of antenna assemblies may be uniform or non-uniform.
Further, an even number of the antenna assemblies 2 are respectively arranged on two opposite sides of the PCB board 1, and the even number of the antenna assemblies 2 are symmetrically distributed on each side.
As can be seen from the above description, the plurality of antenna elements 2 on the left and right sides are respectively disposed symmetrically back and forth.
Example 1
Referring to fig. 1 and 2, a first embodiment of the invention is as follows: an ultra-wideband 5G MIMO antenna structure is mainly used for 5G communication of mobile terminals such as mobile phones and the like, and coexists with a 4G LTE communication system (and other antennas such as GPS and the like), and the existing 4G LTE antenna is already placed on two short sides of the mobile phone, so that the optimal placement position of the 5G MIMO antenna system in the mobile phone is two long sides of the mobile phone.
The ultra-wideband 5G MIMO antenna structure mainly comprises a PCB (printed circuit board) 1 and more than one antenna component 2, wherein the more than one antenna components 2 are arranged on the PCB 1 at intervals. Preferably, the number of the antenna assemblies 2 is an even number more than four, and the even number of the antenna assemblies 2 more than four are symmetrically distributed on two opposite sides of the PCB board 1. In this embodiment, the size of the PCB board 1 is 150mm x75mmx0.8mm, the number of the antenna assemblies 2 is eight, the eight antenna assemblies 2 are symmetrically distributed at the left and right long sides of the PCB board 1, and the intervals between the antenna assemblies 2 on each side are uniform, however, in other embodiments, the intervals between adjacent antenna assemblies 2 may also be non-uniform. As shown in fig. 2, the two long sides of the PCB board 1 are respectively provided with four antenna assemblies 2, and the four antenna assemblies 2 are symmetrically distributed on each side, that is, the four antenna assemblies 2 are symmetrical with respect to the center of the long side of the PCB board 1.
The antenna assembly 2 comprises a feed unit 21 and a grounding radiation unit 22, wherein the feed unit 21 and the grounding radiation unit 22 are respectively supported on a plastic bracket. The feeding unit 21 is disposed corresponding to the position of the feeding point on the PCB board 1, and the ground radiating unit 22 is coupled to the feeding unit 21.
As shown in fig. 3, the ground radiating unit 22 includes a horizontal radiator 221, a first vertical radiator 222, a second vertical radiator 223, and an additional radiator 224, the horizontal radiator 221 is disposed parallel to the PCB board 1, the first vertical radiator 222 and the second vertical radiator 223 are disposed perpendicular to the PCB board 1, and the length of the second vertical radiator 223 is smaller than that of the first vertical radiator 222. The top end of the first vertical radiator 222 is connected to the middle part of the horizontal radiator 221, and the bottom end of the first vertical radiator 222 is connected to a grounding point on the PCB board 1; the top end of the second vertical radiator 223 is connected to the right end of the horizontal radiator 221, and a space is provided between the bottom end of the second vertical radiator 223 and the PCB board 1; the additional radiator 224 is connected to the middle portion of the first vertical radiator 222, and the additional radiator 224 and the first vertical radiator 222 are integrally disposed, which is equivalent to a portion of the first vertical radiator 222 protruding outwards. Preferably, the entire ground radiating element 22 is integrally provided. The additional radiator 224 is connected to a side of the first vertical radiator 222 remote from the second vertical radiator 223, for example, when the second vertical radiator 223 is located on the right side of the first vertical radiator 222, the additional radiator 224 is connected to the left side of the first vertical radiator 222. The additional radiator 224 is rectangular in shape, the additional radiator 224 has a width greater than that of the first vertical radiator 222, and the additional radiator 224 has a length less than that of the first vertical radiator 222.
The feeding unit 21 is disposed at a side of the grounding radiation unit 22, and a plane where the feeding unit 21 is located is parallel to a plane where the grounding radiation unit 22 is located. In this embodiment, the feeding unit 21 is T-shaped, the feeding unit 21 includes a horizontal branch 211 and a vertical branch 212, a top end of the vertical branch 212 is connected to a middle part of the horizontal branch 211, and a bottom end of the vertical branch 212 includes a feeding point; the horizontal branch 211 is arranged close to the horizontal radiator 221 and the vertical branch 212 is arranged close to the additional radiator 224. Preferably, the projection of the horizontal branch 211 in the plane of the ground radiating element 22 overlaps with the horizontal radiator 221 (the top of the horizontal branch 211 overlaps with the bottom of the horizontal radiator 221); the vertical branch 212 has a projection in the plane of the ground radiating element 22 that partially overlaps the additional radiator 224 (the right side of the vertical branch 212 partially overlaps the left side of the additional radiator 224).
The ultra-wideband 5G MIMO antenna structure has high frequency resonance generated by the feed unit 21 and low frequency resonance generated by the ground radiating unit 22, and the antenna structure effectively utilizes the special structures of the antenna feed unit 21 and the ground radiating unit 22 to form two adjacent double resonances, thereby having ultra-bandwidth. By adjusting the dimensions of the feed element 21 and the ground radiating element 22 coupled thereto and their relative positions of the ultra wideband 5G MIMO antenna structure, it will be possible to produce a resonant frequency covering 3.3GHz-5 GHz.
We simulated the 8x8 ultra wideband 5G MIMO antenna and obtained the following results: fig. 4 is an S-parameter diagram of four antenna elements 2 on a single side of the PCB 1 (note: since the ultra wideband 5G MIMO antenna structure has symmetry centered on the PCB 1, only the results of the necessary antenna elements 2 are shown in the above figures, and the following is true). Four antenna assemblies 2 are represented by antenna 1, antenna 2, antenna 3 and antenna 4 in that order. As can be seen from FIG. 4, the working range of the antenna structure is between 3.3GHz and 5GHz, the reflection coefficient of the antenna is better than 6dB, the isolation between the antennas is better than 13dB (especially, the isolation is better than 20dB in high-frequency operation), and the requirements of the isolation between the antennas in the handheld device are met. Since the result in fig. 4 is obtained when the distances between the feed points of the 4 antenna assemblies 2 are equidistant, the isolation between the antenna assemblies 2 can be further optimized by appropriately adjusting the distances between the antenna assemblies 2.
Fig. 5 is a plot of total efficiency of an antenna as a function of frequency. As can be seen from fig. 5, the total efficiency of the antenna is better than 63% in the 5G frequency bands 3.3GHz-3.6GHz and 4.8GHz-5GHz planned in China, and the efficiency in the 3.3GHz-5GHz full frequency band is better than 58%.
Fig. 6 is a graph showing the envelope correlation coefficient of the adjacent antenna assembly 2 as a function of frequency, and it can be seen from fig. 6 that the envelope correlation coefficient of the adjacent antenna assembly 2 is less than 0.05 at 3.3GHz-5 GHz.
The antenna indexes shown in fig. 4, 5 and 6 can completely meet the use requirement of the 5G MIMO antenna structure below 6GHz in a mobile phone.
To further illustrate the principle of operation of the antenna structure, we can observe and analyze the current profile on the antenna assembly 2 when the antenna is operated at frequencies of 3.4GHz and 4.9GHz, respectively. For simplicity we will only analyze the operation of the antenna 1. Fig. 7 is a current distribution diagram of the antenna when the frequency is equal to 3.4GHz, and as can be clearly seen from fig. 7, the current is mainly distributed on the first vertical radiator 222, the additional radiator 224 and the horizontal radiator 221, and the additional radiator 224 prolongs the current path, so that the bandwidth of the low frequency of the antenna is effectively widened. The second vertical radiator 223 can effectively reduce the size of the antenna in the horizontal direction, and change the overall current distribution of the antenna, so that the antenna has good isolation performance during high-frequency operation. Fig. 8 shows the current distribution when the antenna is operated at a frequency equal to 4.9GHz, and as can be seen from fig. 8, the current is mainly distributed over the T-shaped feed element 21 of the antenna.
To further illustrate the advantages of the present antenna, fig. 9 shows a pattern of the antennas 1-4 operating at 4.9GHz, and it can be seen from fig. 9 that the maximum gain direction of each antenna assembly 2 is different when the antennas operate at a high frequency band (4.8 GHz-5 GHz), so that a good isolation between the antennas is ensured (about 20dB is better, see fig. 4).
The embodiment only analyzes and describes the 5G 8x8MIMO which works at the frequency range of 3.3GHz-5GHz below 6GHz, but the antenna design principle of the invention can also be extended to other working frequency ranges and other mxn (m and n are integers more than 2) MIMO antenna systems.
Example two
Referring to fig. 10, the difference between the present embodiment and the first embodiment is that: the feeding unit 21 is L-shaped, the top end of the vertical branch 212 is connected to the end of the horizontal branch 211, and the horizontal branch 211 and the second vertical radiator 223 are located on the same side of the vertical branch 212. As shown in fig. 10, when the second vertical radiator 223 is connected to the right end of the horizontal radiator 221, the second vertical radiator 223 is located on the right side of the vertical branch 212, and the horizontal branch 211 is connected to the right side of the top end of the vertical branch 212. The feeding unit 21 is also capable of generating high frequency resonance.
Example III
Referring to fig. 11, the difference between the present embodiment and the first embodiment is that: the feeding unit 21 is L-shaped, the top end of the vertical branch 212 is connected to the end of the horizontal branch 211, and the horizontal branch 211 and the second vertical radiator 223 are respectively located at two opposite sides of the vertical branch 212. As shown in fig. 11, when the second vertical radiator 223 is connected to the right end of the horizontal radiator 221, the second vertical radiator 223 is located at the right side of the vertical branch 212, and the horizontal branch 211 is connected to the left side of the top end of the vertical branch 212. The feeding unit 21 is also capable of generating high frequency resonance.
In summary, the ultra wideband 5G MIMO antenna structure provided by the present invention is suitable for 5G communication of a mobile terminal, and can effectively cover all frequency bands at 6GHz in 5G mobile communication, and the performance of the antenna can meet the requirements, and when the antenna works at high frequency, there is good isolation between the antennas.
The foregoing description is only illustrative of the present invention and is not intended to limit the scope of the invention, and all equivalent changes made by the specification and drawings of the present invention, or direct or indirect application in the relevant art, are included in the scope of the present invention.